The Advanced Answer option is only available for multi-choice questions where a single answer is correct, not multi-answer questions wherer two or more answers may be correct.

If you need to construct such a question and have branching or feedback appear based on the actual answers the user selected, then you would need to construct this question on a normal Captivate slide using interactive objects, widgets, variables, advanced actions, and text captions. The complexity of the task would depend very much on exactly what you needed to do.

Is what you have stated already (that the feedback caption tells them they have one of the correct answers but there is another one) the only requirement?

1. If some choices that the user selects are not correct (for example, the user selects AB), then prompt with the message "That's not correct. Please try again."

2. If the choices that the user selects are correct (for example, the user selects B), but there are more correct answers, then prompt with the message "There are more correct answers. Please try again."

3. If the user gets all the questions correct (in this example, the user selects BD), then prompt with the message "Well done. That's the correct answer."

Popping in to give you a link to a blogs post with some articles I published about creating custom questions. If you do not have to report to a LMS, that will be the way to go to have total control. Perhaps You'll find some inspiration there: